This invention generally relates to a pinion gear having a metal portion and a plastic portion that is useful for a starting system for small engines.
Starting systems in small engines typically include and electric starting motor. An electric starting motor typically includes a plastic spline shaft that extends out of a motor housing. A plastic pinion gear is supported on the spline shaft and is engaged by a driving member or a ring gear. The pinion gear and the spline shaft driven by the starter motor rotate, causing the pinion gear to engage the drive member (ring gear), which starts the engine.
Since plastic spline shafts are used, plastic pinion gears typically were required. Metal pinion gears could not be used because of the undesirable wear caused on the spline shaft during typical starting cycles. Plastic pinion gears are not as durable as desired because the engagement of the driving member on the plastic gear teeth causes wear.
Therefore, there is a need for an improved pinion gear that will be more durable and still be accommodated on the plastic spline shafts typically associated with small engine starting systems.